title: Atrial fibrillation in myocardial infarction patients: Impact on health care utilization.
abstract: BACKGROUND
  Atrial fibrillation (AF) often complicates myocardial infarction (MI). While AF adversely impacts survival in MI patients, the impact of AF on health care utilization has not been studied.
  
  
  METHODS
  The risk of hospitalizations, emergency department (ED) visits, and outpatient visits associated with prior, new-onset (<30 days post-MI), and late-onset (≥30 days post-MI) AF was assessed among incident MI patients from the Olmsted County, Minnesota, community.
  
  
  RESULTS
  Of 1,502 MI patients, 237 had prior AF, 163 developed new-onset AF, 113 developed late-onset AF, and 989 had no AF. Over a mean follow-up of 3.9 years, 3,661 hospitalizations, 5,559 ED visits, and 80,240 outpatient visits occurred. After adjustment, compared with patients without AF, those with prior and new-onset AF exhibited a 1.6-fold and 1.3-fold increased risk of hospitalization, respectively. In contrast, late-onset AF carried a 2.2-fold increased risk of hospitalization. The hazard ratios were 1.4, 1.2, and 1.8 for ED visits and 1.4, 1.2, and 1.7 for outpatient visits for prior, new-onset, and late-onset AF. Additional adjustment for time-dependent recurrent MI and heart failure attenuated the results slightly for hospitalizations and ED visits; however, patients with late-onset AF still exhibited a >50% increased risk for both utilization measures.
  
  
  CONCLUSIONS
  In MI patients, the risk of hospitalizations, ED visits, and outpatient visits differed by the timing of AF onset, with the greatest risk conferred by late-onset AF. Atrial fibrillation imparts an adverse prognosis after MI, underscoring the importance of its management in MI patients.
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, MN.
authors.forename: Alanna M
authors.initials: AM
authors.lastname: Chamberlain
authors.forename: Suzette J
authors.initials: SJ
authors.lastname: Bielinski
authors.forename: Susan A
authors.initials: SA
authors.lastname: Weston
authors.forename: Winslow
authors.initials: W
authors.lastname: Klaskala
authors.forename: Roger M
authors.initials: RM
authors.lastname: Mills
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Gersh
authors.forename: Alvaro
authors.initials: A
authors.lastname: Alonso
authors.forename: Véronique L
authors.initials: VL
authors.lastname: Roger
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000453:epidemiology / Q000209:etiology* / Q000628:therapy; D004562:Electrocardiography; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D009203:Myocardial Infarction / Q000150:complications* / Q000628:therapy; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D014600:Utilization Review / Q000379:methods*